We don't yet know what the full red uniform will look like, but both the Bills' and the Jets' outfits will be revealed in full during next Thursday night's game between Cincinnati and Cleveland. It is, of course, possible that the uniforms leak beforehand, as well.
The Bills-Jets game will be the first of four in which Nike and the NFL make TNF participant teams wear these uniforms as part of a "NFL Color Rush" campaign that purports to "unify fans and communities around a current or historic color," which basically means that they want you to buy them. (They'll be on sale on November 5-6, by the way.)
If this is a dream come true for you, and you're worried that it'll only be a one-time deal, fear not: this four-game stretch is essentially a beta release for the Color Rush campaign. In 2016, every team in the league will have a Color Rush alternate, and as every NFL team plays at least once on Thursday, it's very likely that we'll see the Bills' red uniforms again.